In recent years, high-speed interfaces as devices used for input and output of data between apparatuses have been realized. High-speed interfaces are utilized for communication between Large-Scale Integrated (LSI) chips on a board, communication between boards, communication between chassis using an optical cable, and the like.
As a standard that specifies the specifications of high-speed interfaces, for example, PCI Express is known. PCI Express is a standard regarding not parallel communication in which a large number of signal lines are used but serial communication in which a protocol based on packets is adopted.
A high-speed interface has a buffer that receives data which is transmitted at high speed, and a control circuit that performs order control and flow control. The buffer and the control circuit are provided as, for example, a programmable logic device (PLD), a Field-Programmable Gate Array (FPGA), or an application-specific integrated circuit (ASIC). An example of the related art is disclosed in Japanese Unexamined Patent Application Publication No. 2005-158076.
When one of apparatuses that perform input and output of data between each other has a high-speed interface, the other apparatus also needs to have a high-speed interface. Therefore, even in the case of communication between two points for which high-speed communication is not necessary, when one of apparatuses has a high-speed interface, the other apparatus needs to have a high-speed interface.